Insulated container for and method of cooling a heated tooling component

ABSTRACT

Disclosed is an insulated container  2  for cooling a heated tooling component  4 . The insulated container  2  comprises: a housing including a thermally insulated base  6 , an insulated side wall  10  and an insulated upper wall  12  which define a chamber  36  for receiving the tooling component  4 ; an inlet port  30  passing through the insulated base  6 , the inlet port  30  allowing ambient air to enter the chamber  36 ; and a vent  18  passing through the insulated upper wall  12 , the vent  18  allowing air heated by the heated tooling component  4  to be ejected such that a convective air flow through the chamber  36  cools the tooling component  4 , wherein a flow area of the vent  18  can be varied to allow an air flow rate through the chamber  36  to be controlled. There is also disclosed a method of cooling a heated tooling component  4.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from British Patent Application Number 1621376.1 filed 15 Dec. 2016, the entire contents of which are incorporated by reference.

BACKGROUND 1. Field of the Disclosure

The disclosure relates to an insulated container for and method of cooling a heated tooling component.

2. Description of the Related Art

A variety of hot forming processes are known and currently used in industry. One such hot forming process is superplastic forming (SPF). SPF involves heating sheet metal such that it exhibits superplasticity, and subsequently forming it using techniques normally used for forming plastics. During SPF, in addition to heating the sheet metal itself, it is also necessary to heat the tooling components used to form the sheet metal. This maintains the temperature of the sheet metal whilst it is being formed. However, since the tooling components have non-uniform thickness, after the forming process is complete, the tooling components cool in a non-uniform manner, which leads to the establishment of temperature differentials and thermal stresses within the component. Such thermal stresses can lead to distortion and cracking of the tooling components, which are expensive and time-consuming to replace.

It is therefore desirable to provide a way of overcoming or alleviating some or all of these issues.

SUMMARY

In accordance with a first aspect, there is provided an insulated container for cooling a heated tooling component. The insulated container comprises: a housing formed by a thermally insulated base, a thermally insulated side wall and a thermally insulated upper wall which define a chamber for receiving the heated tooling component; an inlet port passing through the thermally insulated base, the inlet port allowing ambient air to enter the chamber; and a vent passing through the thermally insulated upper wall, the vent allowing air that has been heated by the heated tooling component to be ejected such that a convective air flow through the chamber is generated to cool the tooling component, wherein a flow area of the vent can be varied so as to allow an air flow rate through the chamber to be controlled.

The vent may comprise an opening passing through the thermally insulated upper wall from the chamber to an exterior of the insulated container.

The opening may pass through a central portion of the thermally insulated upper wall. The opening may be symmetric about a plane passing through a central axis of the housing.

The opening may be rotationally symmetric about a central axis of the housing.

An internal profile of the opening may be in the shape of an inverted frustum.

The internal profile of the opening may be in the shape of an inverted frustum of a square pyramid.

The vent may further comprise a valve member actuable between a first position and a second position in order to change a size of a gap formed between the opening and the valve member.

An external profile of the valve member may substantially correspond to an internal profile of the opening.

When the valve member is in the second position, the opening may be closed so no gap exists between the opening and the valve member.

The valve member may be actuable to a range of positions between the first position and the second position.

The valve member may be linearly actuable.

The insulated container may further comprise a linear cam. The valve member may be linearly actuable by the linear cam.

The valve member and/or the housing may comprise one or more guiding projections.

The guiding projections may be slidably receivable within one or more complementary recesses provided in the other of the valve member and/or the housing.

The valve member may be aligned centrally relative to the opening.

The thermally insulated base may be formed as a first component and the thermally insulated side and upper walls may be formed as a second component. The second component may be detachably coupled to the first component so as to permit insertion and removal of the heated tooling component into and from the chamber.

The base may comprise one or more projections extending from a body of the base for supporting the heated tooling component above the body of the base such that it is spaced therefrom by an air gap.

The one or more projections may extend through the base so as to form a rigid strut.

The container may comprise a plurality of said inlet ports passing through the thermally insulated base. The plurality of inlet ports may be evenly distributed across the thermally insulated base.

The heated tooling component may be a heated tooling component used in a superplastic forming process.

In accordance with a second aspect, there is provided a method of cooling a heated tooling component, the method comprising: heating a tooling component during a superplastic forming process; positioning the heated tooling component in a chamber of an insulated container, the insulated container comprising an inlet port passing into the chamber from an exterior of the insulated container and a vent passing out of the chamber to an exterior of the insulated container; and retaining the heated tooling component in the chamber for a period of time such that air within the chamber is heated by the heated tooling component and ejected through the vent and ambient air enters the chamber through the inlet port, thereby generating a convective air flow through the chamber to cool the heated tooling component.

The method may comprise varying a flow area of the vent so as to allow an air flow rate of the convective air flow through the chamber to be controlled.

The vent may comprise an opening and a valve member. The step of varying the flow area of the vent may comprise varying the extent by which the valve member occludes the opening.

The step of varying the extent by which the valve member occludes the flow area may comprise linearly actuating the valve member between a first position and a second position relative to the opening.

The chamber may be defined by a thermally insulated base, a thermally insulated side wall and a thermally insulated upper wall. The thermally insulated base may be detachably coupled to the thermally insulated side wall. The step of positioning the heated tooling component in the chamber may comprise separating the thermally insulated side wall from the thermally insulated base, positioning the heated tooling component on the base, and coupling the thermally insulated side wall to the thermally insulated base.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the disclosure and to show more clearly how it may be brought into effect, the disclosure will now be described, by way of reference only, to the accompanying figures, in which:

FIG. 1 is a perspective view of an insulated container for cooling a heated tooling component;

FIG. 2 is a perspective view of a base of the insulated container;

FIG. 3 is a perspective view of a cover of the insulated container;

FIG. 4 is a perspective view of a valve member of the insulate container;

FIG. 5A is a cross-sectional view of the insulated container, in use and with the valve member in a first position; and

FIG. 5B is a cross-sectional view of the insulated container, in use and with the valve in a second position.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIG. 1 shows an insulated container 2 for cooling a heated tooling component 4 (see FIGS. 5A and 5B). The insulated container 2 generally comprises a thermally insulated base 6 and a thermally insulated cover 8, which together form a housing. The thermally insulated cover 8 comprises four thermally insulated side walls 10 and a thermally insulated upper wall 12 connected to the side walls 10. A lower surface 14 (see FIGS. 5A and 5B) of the cover 8 is detachably coupled to an upper surface 16 (see FIG. 2) of the base 6. Consequently, the cover 8 is detachably coupled to the base 6. A vent 18 passes through the upper wall 12. The vent 18 generally comprises an opening 20 passing through the upper wall 12, a valve member 22 and a linear actuator 24.

FIG. 2 shows the base 6 in isolation. The base 6 comprises a metal exterior and an insulating core. The base 6 is substantially cuboid in shape, has a substantially square profile when viewed from above and is substantially planar. A central portion of the upper surface 16 of the base 6 is provided with a plurality of small projections 26 in the form of linear fins or ridges which extend upwards from the upper surface 16 of the base 6. The projections 26 are arranged in a grid-like formation and extend in a downward direction through the interior of the base 6 to a lower surface 28 (see FIGS. 5A and 5B) of the base 6. Each individual projection 26 connects directly to the lower surface 28 of the base 6. Consequently, the projections 26 form a rigid compressive strut, which increases the structural rigidity of the base 6. A peripheral border of the upper surface 16 of the base 6 is not provided with any such projections. Consequently, the peripheral border of the upper surface 16 of the base 6 is flat and forms a suitable landing site for receiving the lower surface 14 of the cover 8.

The base 6 further comprises a plurality of (in this example five) inlet ports 30. The inlet ports 30 extend from the lower surface 28 of the base 6 to the upper surface 16 of the base 6 such that fluid communication is established therebetween. The inlet ports 30 are arranged in a formation which is symmetric about any plane passing through a centre of the base 6. Further, the formation of the inlet ports 30 is rotationally symmetric about the centre of the base 6. Specifically, one of the inlet ports 30 is provided at the centre of the base 6 on the central axis 38 and the other inlet ports 30 are provided at the corners of a square which is centred on the central axis 38. In addition, the base 6 comprises a plurality of (in this example eight) lifting hook apertures 32. The lifting hook apertures 32 allow lifting hooks to be attached to the base 6 such that the base 6 (in isolation or in combination with the cover 8) may be lifted. Two lifting hook apertures 32 are provided on each side surface of the base 6.

FIG. 3 shows the cover 8 in isolation, with the valve member and actuator 24 removed. As per the base 6, the cover 8 comprises a metal exterior and an insulating core. The cover 8 is substantially cuboid in shape, and has a square profile when viewed from above that corresponds to the square profile of the base 6. As best shown in FIGS. 5A and 5B, an interior surface 34 of the cover 8 defines a chamber 36 which is open at the lower surface 14 of the cover 8. The opening 20 passes through the upper wall 12 into the chamber 36.

The opening 20 passes through a central portion of the upper wall 12. In particular, the opening 20 passes through a central portion of the upper wall 12 when viewed from above. The opening 20 is symmetric about any plane passing through a central axis 38 of the cover 8. Further, the opening 20 is rotationally symmetric about the central axis 38 of the cover 8.

As best shown in FIGS. 5A and 5B, the interior surface or internal profile of the opening 20 is in the form of an inverted pyramidal frustum. Specifically, the interior surface of the opening 20 is in the form of an inverted frustum of a square pyramid. In other words, the interior surface of the opening 20 has a square profile when viewed from above which tapers inwardly in a downward direction. The interior surface (side wall) of the opening 20 is provided with a plurality of slots 40. Each interior surface of the opening 20 is provided with a slot 40, such that the opening 20 has four slots 40 in total. The slots 40 each run from towards a lower surface of the upper wall 12 towards an upper surface of the upper wall 12. The slots 40 each pass through the centre or centroid of the interior surface.

In addition, the cover 8 comprises a plurality of (in this example eight) lifting hook apertures 42. The lifting hook apertures 42 allow lifting hooks to be attached to the cover 8 such that the cover 8 (in isolation or in combination with the base 6) may be lifted. Two lifting hook apertures 42 are provided on each side surface of the cover 8. FIG. 4 shows the valve member 22 in isolation. As per the base 6 and the cover 8, the valve member 22 comprises a metal exterior and an insulating core. An upper surface 44 of the valve member 22 is provided with a guide 46. The exterior surface or external profile of the valve member 22 is in the form of an inverted pyramidal frustum. Specifically, the exterior surface of the valve member 22 is in the form of an inverted frustum of a square pyramid. In other words, the exterior surface of the valve member has a square profile when viewed from above, which tapers inwardly in a downwards direction. The exterior surface of the valve member 22 substantially corresponds to the interior surface of the opening 20. Consequently, the exterior surface of the valve member 22 is able to seal against the interior surface of the opening 20, which thus acts as a valve seat. The lower surface 48 of the valve member 22 in particular acts as a bottom sealing plate capable of sealingly engaging the interior surface 34 of the cover 8.

The exterior surface of the valve member 22 is provided with a plurality of guide fins 50. Each side of the exterior surface of the valve member 22 is provided with a single guide fin 50, such that the valve member 22 has four guide fins 50 in total. The position of the guide fins 50 corresponds to the position of the slots 40 such that the slots 40 receive the guide fins 50 when the valve member 22 is positioned within the opening 20.

The interaction between the slots 40 and guide fins 50 prevent rotational movement of the valve member 22 about the central axis 38, but permit sliding movement of the valve member 22 in a vertical direction. Such vertical movement is effected by the actuator 24. The actuator 24 comprises a first support bracket 52, a second support bracket 54 and a sliding cam member 56. The cam member 56 is slidably supported by the first and second support brackets 52, 54 which are located on opposite sides of the opening 20. The cam member 56 passes through an opening formed in the guide 46. The cam member 56 comprises upper and lower parallel portions 57 a, 57 b and an angled central portion 58 disposed between the parallel portions 57 a, 57 b. The angled central portion 58 is such that the parallel portions 57 a, 57 b are parallel to one another, but offset vertically from one another. The first and second support brackets 52, 54 are arranged to support the upper and lower parallel portions 57 a, 57 b at different heights to account for this vertical offset. The cam member 56 is slidable relative to the first and second support brackets 52, 54 and the guide 46 such that the guide 46 slides along the central angled portion 58. As the guide 46 slides from towards the upper parallel portion 57 a towards the lower parallel portion 57 b, the valve member 22 is lowered into the opening 20. Conversely, as the guide 46 slides from towards the lower parallel portion 57 b towards the upper parallel portion 57 a the valve member 22 is raised out of the opening 20. In this manner, the cam member 56 acts as a cam and the guide 46 acts as a cam follower. This function will be described further below. The cam member 56 is provided with a scale 60 along the lower parallel portion 57 b (although it could be provided on the upper parallel portion 57 a instead or in addition) to allow the position of the cam member 56 relative to the support brackets 52, 54 to be easily determined. The valve member 22 is located centrally within the opening 20 such that the vent 18 as a whole is symmetric about any plane passing through a central axis 38 of the cover 8, and is rotationally symmetric about the central axis 38 of the cover 8.

The insulated container 2 is employed after an SPF process is performed in which sheet metal is heated to an SPF temperature and then formed to a desired shape. A tooling component 4, such as a mould or die is also heated. The tooling component 4 may weigh between a few kilograms and upwards of 2,000 kilograms.

To use the insulated container 2, the user first detaches the cover 8 from the base 6. This may be carried out using the lifting hook apertures 42. The user then places the heated component 4 on the central portion of the upper surface 16 of the base 6. The heated component 4 is placed on the projections 26 such that the heated component 4 is supported above the upper surface 16 of the base 6. Consequently, an air gap 62 is formed between the upper surface 16 of the base 6 and the component 4 (see FIGS. 5A and 5B). The user then reattaches the cover 8 to the base 6, such that the heated component 4 is disposed within the chamber 36. Again, this may be accomplished with the aid of the lifting hook apertures 42.

FIG. 5A shows the valve member 22 in a first position. In the position, the cam member 56 is positioned so that the guide 46 is supported at or towards the upper parallel portion 57 a. In this position, the valve member 22 is raised out of the opening 20 such that a perimetral (i.e. annular) air gap 64 is formed between the interior surface of the opening 20 and the exterior surface of the valve member 22.

With the component 4 positioned within the chamber 36, air within the chamber 36 is heated up by the component 4 and rises towards the opening 20, where it exits the insulated chamber 2 into the surrounding atmosphere. In this manner, the cover 8 acts as a chimney. This causes, relatively cool ambient air from outside of the insulated container 2 to be drawn up through the inlet ports 30 into the chamber 36. Due to the presence of the air gap 62, the air is able to travel from the inlet ports 30 and into the chamber 36 by passing around the component 4. Consequently, the residual thermal energy of the component 4 helps to create convection currents within the chamber 36, which cool the component 4, and, as a result, the insulated container 2 provides self-powered cooling to the component 4.

Since the inlet ports 30 are evenly distributed across the base 6, the air from the inlet ports 30 wraps around or embraces the entirety of the component 4. Consequently, the component 4 is cooled uniformly across its surface. In addition, since the vent 18 passes through a central portion of the upper wall 12 and is symmetric, venting-symmetry in a plane perpendicular to the convected air flow prevents spatial bias in vent-induced convection currents. This further ensures that air flows evenly around the component 4, thus promoting uniform cooling of the component 4.

In addition to providing an air gap 62 between the upper surface 16 of the base 6 and the component 4, the projections 26 also minimise the contact area between the insulated container 2 and the component 4, thus reducing the amount of thermal energy extracted from the component 4 into the insulated container 2 via conduction. Consequently, the thermal energy of the component 4 is almost entirely dissipated therefrom through controlled convection and radiation. In addition, as mentioned previously, the projections 26 form a rigid compressive strut. Consequently, when the component 4 is placed on the base 6, the base 6 is able to support the component 4 without the base 6 drooping or sagging under the force of gravity. This in turn prevents the component 4 itself drooping or sagging under the force of gravity.

In the first position shown in FIG. 5A, the cam member 56 is actuated to its maximum vertical (i.e. highest/fully raised) position. Consequently, the air gap 64 is at its maximum size and the flow rate through the chamber 36 is maximised. The user may reduce the size of the air gap 64 (and thus the flow rate through the chamber 36) by sliding the cam member 56 so that the guide 46 rides down the central angled portion 58 of the cam member 56 towards the lower parallel portion 57 b. The valve member is therefore lowered toward the opening 20.

FIG. 5B shows the valve member 22 in a second position. In the second position, the user has actuated the cam member 56 to its minimum vertical (i.e. lowest/fully lowered) position by sliding the cam member 56 so that the guide 46 rides down the central angled portion 58 towards the lower parallel portion 57 b. In this position, the exterior surface of the valve member 22 seals against the interior surface of the opening 20. The lower surface 48 of the valve member 22 in particular acts as a bottom sealing plate that sealingly engages the interior surface 34 of the cover 8. In the second position, there is no perimetral air gap 64 and, as such, air heated by the component 4 is unable to exhaust out of the chamber 36. Consequently, the level of convection within the chamber 36 is significantly reduced in comparison to first position, and the rate of cooling of the component 4 thus also reduced.

The first and second positions mentioned above represent two extremes of valve member 22 height, and thus gap 64 size. Specifically, in the first position, the valve member 22 is at its maximum height and thus the gap 64 is at its maximum size, whereas in the second position, the valve member 22 is at its minimum height and thus the gap 64 is at its minimum size (i.e. closed). However, the user is able to position the valve member 22 at any position between the maximum and minimum heights by sliding the cam member 56 to any position between the position of the member 56 shown in FIG. 5A and the position shown in FIG. 5B. Accordingly, the user is able to select an appropriate level of convection within the chamber 36, and thus an appropriate rate of cooling of the component 4. The position of the valve member 22, the size of the gap 64 or the rate of convection or cooling may be determined from the scale 60.

The area (i.e. the flow area) of the perimetral gap 64 is approximately proportional to the height of the valve member 22. The relationship between the height of the valve member 22 and the area of the perimetral gap 64 is approximately linear, provided the width of the gap 64 is less than 25% of the width of the opening 20 (i.e. the length of one of the square sides of the opening 20), as measured at the upper surface of the upper wall 12. The valve member 22 is actuated linearly by the actuator 24 within the opening 20 such that the symmetry of the vent 18 is maintained regardless of the height of the valve member 22.

By way of example, a user may wish to set a small gap 64 size when cooling components 4 having a small mass. Conversely, a user may wish to set a large gap 64 size when cooling components 4 having a large mass. This may therefore ensure a substantially uniform rate of cooling regardless of the size of the component. This allows the insulated container 2 to be used for a range of different components and so avoids needing different sized containers. The user may wish to maximise the size of the gap 64 so as to increase the rate of cooling. However, the user may wish to maximise the size of the gap 64 only to the extent that distortion and cracking of the component 4 is still prevented.

As previously mentioned, the valve member 22 is itself insulated. Accordingly, when the valve member 22 is in the fully closed position such as that shown in FIG. 5B, it provides an insulating function to the chamber 36. Consequently, in the position shown in FIG. 5B, the valve member 22 not only prevents convective cooling of the component 4 but also conductive cooling of the component 4 through the thermally insulated upper wall 12. When the valve member 22 is in any position other than a fully downwards position (i.e. the position shown in FIG. 5B), the insulating properties of the valve member 22 have no effect on the rate of cooling of the component 4. Instead, the rate of cooling of the component 4 is entirely dependent on the width of the gap 64.

Although it has been described that the valve member 22 is able to move to a fully closed position such that a seal is formed between an exterior surface of the valve member 22 and the interior surface of the opening 20, in other arrangements the valve member 22 may be prevented from fully occluding the opening 20 such that the gap 64 can never be fully closed.

Although it has been described that the opening 20 and valve member 22 have profiles corresponding to inverted frustums of a square pyramid, they may alternatively have profiles corresponding to inverted frustums of any other type of pyramid or cone, for example a circular or elliptical cone. The vent 18 may also be closed using any other type of valve which allows the size of the opening to be controlled and which maintains a uniform flow of air through the vent 18.

It will be appreciated that the arrangement of the slots 40 and guide fins 50 may be reversed. Further, the valve member 22 may be raised and lowered using other arrangements instead of the cam member 56.

Although it has been described that the insulated container 2 is for cooling a heated tooling component 4, the insulated container 2 may be for cooling a heated component of any type. 

1. An insulated container for cooling a heated tooling component, the insulated container comprising: a housing formed by a thermally insulated base, a thermally insulated side wall and a thermally insulated upper wall which define a chamber for receiving the heated tooling component; an inlet port passing through the thermally insulated base, the inlet port allowing ambient air to enter the chamber; and a vent passing through the thermally insulated upper wall, the vent allowing air that has been heated by the heated tooling component to be ejected such that a convective air flow through the chamber is generated to cool the tooling component, wherein a flow area of the vent can be varied so as to allow an air flow rate through the chamber to be controlled.
 2. An insulated container as claimed in claim 1, wherein the vent comprises an opening passing through the thermally insulated upper wall from the chamber to an exterior of the insulated container.
 3. An insulated container as claimed in claim 2, wherein the vent further comprises a valve member actuable between a first position and a second position in order to change a size of a gap formed between the opening and the valve member.
 4. An insulated container as claimed in claim 3, wherein an external profile of the valve member substantially corresponds to an internal profile of the opening.
 5. An insulated container as claimed in claim 3, wherein when the valve member is in the second position, the opening is closed so no gap exists between the opening and the valve member.
 6. An insulated container as claimed in claim 3, wherein the valve member is actuable to a range of positions between the first position and the second position.
 7. An insulated container as claimed in claim 3, wherein the valve member is linearly actuable.
 8. An insulated container as claimed in claim 7, further comprising a linear cam, wherein the valve member is linearly actuable by the linear cam.
 9. An insulated container as claimed in claim 3, wherein the valve member and/or the housing comprise one or more guiding projections slidably receivable within one or more complementary recesses provided in the other of the valve member and/or the housing.
 10. An insulated container as claimed in claim 3, wherein the valve member is aligned centrally relative to the opening.
 11. An insulated container as claimed in claim 1, wherein the thermally insulated base is formed as a first component and the thermally insulated side and upper walls are formed as a second component which is detachably coupled to the first component so as to permit insertion and removal of the heated tooling component into and from the chamber.
 12. An insulated container as claimed in claim 1, wherein the base comprises one or more projections extending from a body of the base for supporting the heated tooling component above the body of the base such that it is spaced therefrom by an air gap.
 13. An insulated container as claimed in claim 12, wherein the one or more projections extend through the base so as to form a rigid strut.
 14. An insulated container as claimed in claim 1, wherein the container comprises a plurality of said inlet ports passing through the thermally insulated base, the plurality of inlet ports being evenly distributed across the thermally insulated base.
 15. An insulated container as claimed in claim 1, wherein the heated tooling component is a heated tooling component used in a superplastic forming process.
 16. A method of cooling a heated tooling component, the method comprising: heating a tooling component during a superplastic forming process; positioning the heated tooling component in a chamber of an insulated container, the insulated container comprising an inlet port passing into the chamber from an exterior of the insulated container and a vent passing out of the chamber to an exterior of the insulated container; and retaining the heated tooling component in the chamber for a period of time such that air within the chamber is heated by the heated tooling component and ejected through the vent and ambient air enters the chamber through the inlet port, thereby generating a convective air flow through the chamber to cool the heated tooling component.
 17. A method as claimed in claim 16, the method comprising varying a flow area of the vent so as to allow an air flow rate of the convective air flow through the chamber to be controlled.
 18. A method as claimed in claim 17, wherein the vent comprises an opening and a valve member, and wherein the step of varying the flow area of the vent comprises varying the extent by which the valve member occludes the opening.
 19. A method as claimed in claim 18, wherein the step of varying the extent by which the valve member occludes the flow area comprises linearly actuating the valve member between a first position and a second position relative to the opening.
 20. A method as claimed in claim 16, wherein the chamber is defined by a thermally insulated base, a thermally insulated side wall and a thermally insulated upper wall, the thermally insulated base being detachably coupled to the thermally insulated side wall, and wherein the step of positioning the heated tooling component in the chamber comprises separating the thermally insulated side wall from the thermally insulated base, positioning the heated tooling component on the base, and coupling the thermally insulated side wall to the thermally insulated base. 